Hubless Frsky telemetry with Baseflight on Naze32

It’s been about 2 weeks now since successfully setting up the stm32f103 toolchain on my mac. Darn that was hard. Anyhow, I wanted to play around with telemetry for the Frsky receivers since ER9X supports it. I do have a hub, but one thing that bothered me was that to get the telemetry, we would be buying and installing a bunch of sensors that our main flight controllers already have.

With this in mind I set about to seeing how Baseflight on the Naze32 could output it’s own sensor readings directly to the Frsky receiver so that we could use those readings instead.

So to cut a long story short, it worked. I submitted the code to Timecop, and he was nice enough to clean it up and merge it into the latest release. We now have telemetry output for:

Barometer

Accelerometer

Gyro temperature

GPS

System up time (in the time field for Frsky)

To activate this you’ll need to download and install the latest revision of Baseflight and enable telemetry with feature TELEMETRY from the CLI. Remember to save after that.

You’ll also need a level shifter between the Naze32 and the Frsky receiver. Below is the design I used. You’ll only need the top TxD -> RxD' portion.

Image from http://www.kswichit.com

Timecop has also designed a small adapter which would be a lot cleaner from an installation standpoint.

Level shifter for Naze32 to Frsky receiver by Timecop.

I’m still hoping to get multi-cell Lipo information as part of the stream and not just VBAT. This will require using something like the FLVS-01 lipo sensor with a direct connection to the Naze32. Gonna take a look at that next.